Pin connector and method of manufacturing the same



Jan. 21, 1964 E. s. CORNELL, JR 3,118,740

PIN CONNECTOR AND METHOD OF MANUFACTURING THE SAME Filed Aug. 25, 1955 2 Sheets-Sheet 1 IN VEN TOR.

L ATTORNEY Jan. 21, 1964 s L, JR 3,118,740

PIN CONNECTOR AND METHOD OF MANUFACTURING THE SAME Filed Aug. 25, 1955 2 Sheets-Sheet 2 i INVENTOR. 1

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United States Patent Ofitice Patented Jan. 21, 1%84:

3,118,745 MN (IGNNECTOR AND BETH-Km) F MANU= FAQTURIN-G THE SAME Edward 5. Cornell, r., Westport, Comm, assigncr to (Zerporation, a corporation of New York Filed Aug. 25, 1955, Ser. No. 530,435 3 Claims. (Cl. 29-4935) This invention relates to pin connectors commonly used as prongs for electrical connection to vacuum tubes, and generally as a plug for readily attachable and detachable connection to and from a socket.

Hitherto, such pin connectors were made from stamped sheet metal or from solid stock turned on an automatic screw machine. In both cases, considerable scrap loss was involved. In the stamping process the tooling charge is expensive; the formed pin is not uniform throughout the structure, and the hollow portion into which the bared wire conductor is to be inserted becomes filled with the plating and cleaning solutions and ofi'ers dificulty in removing the same. in addition, the longitudinal slit formed by rolling the metal edge to edge is objectionable. Copper, which is desirable from the standpoint of conductivity, is not used because it adheres to the tools. As a consequence, brass is used both in the sheet metal and the screw machine pin connectors, although a loss of from 20% to 3 in conductivity is encountered.

Accordingly, the primary object of my invention is to provide a new method of making pin connectors which will provide a stronger pin at less cost and with maximum conductivity.

Other objects are to provide a process of making pin connectors which lends itself to automatic equipment using relatively low cost stock and mounted in position for Wire installation without manual handling.

I accomplish these and other objects and obtain my new results as will be apparent from the device described in the following specification, particularly pointed out in the claims, and illustrated in the accompanying drawing in which:

FIG. 1 is a side elevation of a continuous piece of metal illustrating diagrammatically the various operations which- =rnay be performed upon it during the process of its manur'acture into a pin connector.

FIG. 2 is a plan View of the same.

FIG. 3 is an enlarged side elevation of a for-med pin connector separated from the continuous strip.

FIG. 4 is a plan view or" the same.

FIG. 5 is an end view of the separated connector.

FIG. 6 is a side elevation of the extrusion die and punch for making the same, partly in section.

FIG. 7 is a sectional view of the extrusion die and punch taken along line 77 of HG. 6.

FIGS. 8 and 9 are face views of the punch and die, respectively.

As is indicated in the drawing, I propose to manufacture the pin connectors by cold working extruded wire of desired conductivity. To this end I employ impact tools adapted to shape the wire into the desired form of the pin connector.

I may obtain further advantageous results by applying the impact tools laterally to each side of the extruded wire. To permit this application, 1 have designed a pin connector with a Ushaped portion for receiving the bared end of the conductor.

Specifically, in FIGS. 3, 4 and 5, such pin connector 10 is illustrated. it comprises a preferably tapered pin portion 12 at one end for insertion into a socket of a receiving connector (not shown), and a hollow portion 1 the other end for receiving the bared end of a wire. Intermediate the two ends an insulation locking or tool engaging portion 16 is preefrably provided for insertion into the body of a molded section of insulation to permit a plurality of pins to be aligned side-by-side for multi-connector use if desired, or for enabling a tool to be applied thereto to assist in the connection to a socket. A hollow wire insulation gripping section 18 may also be provided in the pin connector, if needed.

The hollowed out portions 14 and 18 may each be formed in the shape of a U with Wings 2% and 22, respectively. When installed and compressed to the wire, the wings are rounded until the ends abut each other to (form a tubular structure, as is shown in the last station of FIGS. 1 and 2.

As is illustrated in FIG. 6, the cold working dies essentially comprise upper punch 24- and lower die 26. They cold work the wire 28 into the final form of pin connector it allowing for a unitary connecting portion 3% between tormed connectors to the final operation. As shown in FIGS. 1 and 2, unitary connecting portion 30 connects the rear edge 32 of wire insulation gripping portion 18 to the extreme front edge 34- of the pin portion 12.. Upper and lower die blocks 36 and 38 assist in the formation of this connector portion.

Upper punch 24 is shown FIGS. 6, 7 and 8. It comprises a recessed portion 4d for forming the upper half of pin portion -12, a recessed portion 42 for forming the upper half of retaining portion 16, and projections 44 and 46 for forming the U-shaped hollowed out portions 14 and 13, respectively. At the front and rear of the upper punch 24 are unitary connecting-portion-forrning projections 48 and 5%, respectively, which form the upper half of the unitary connecting portion 39 joining edges 32. and

The lower die 2-6 comprises th recessed portions 52, 54-, 55 and 58 for forming the lower half of pin portion 12, retaining portion 16, hollow portion 14, and wire gripping portion 18, respectively. The recessed portion 6%, and forming surface 62, shape the lower faces of front and rear edge connections of the corresponding portions of unitary connecting portion 39.

As is shown in FIGS. 1 and 2, during the extrusion stages, a flash 64 is formed around pin and retaining portions 12 and 16', which is integral with the unitary con nection portion 3 9 between pin connectors. Also flash '66 and 68 is formed at the edges of U-shaped portions 2% and 22, respectively. The flash is removed in the trimming operation shown in dot-dash to complete the finished pin connectors.

In operation, the wire 28 from a continuous coil shown at the left or" FTGS. 1 and 2, is fed into the impact eX- trusion press and converted into the strip. The parts are fed from station to station to form, trim and separate the pin connectors.

in the final operation, see right hand of FIGS. 1 and 2, the pin connectors may be inserted on and secured to a continuous band, not shown, for feeding at some later date into an indenting press where conductor wires are fed into the pin connectors for attachment thereto, for example as is shown in co pending application Serial No. 346,008, which matured to Patent 2,815,124 on December 3, 1957, or the bared end of wire conductor '7@ may instead be inserted directly into the pin connector in the extrusion machine at the final position and crimped as at '72 thereto. The completed and installed connector 74 may be separated from the continuous strip during the crimping operation.

While the invention contemplates the manufacture of the pin in one operation except for trimming the flash, a number of preliminary operations may be employed to congregate the material. Gathering dies may also precede the final stages of the formation of the material as is 63 shown in the initial gathering stage of FIGS. 1 and 2. in all stages it is desirable to connect the partially formed connectors for transporting the same from station to station.

The final worn hardened pin connectors made by my process are more resistant to wear, corrosion, and to axial distortion than the pin connectors made hitherto. Such connectors may be manufactured in quantity at minimum cost, and in various sizes and shapes with minimum loss of scrap. The work hardened pin connectors being preferably made or" pure copper, are more electrically efiicient than simflarly shaped connectors hitherto required to be made of brass. The process is therefore uniquely valuable for manufacturing electrical connectors.

Connectors made in accordance with my process possess to the fullest extent the physical properties necessary to render the same highly eificient, reliable and durable in use, and capable of functioning in a manner far superior to other connectors fabricated in accordance with other methods, and not possessing or capable of possessing the physical characteristics of the connectors embodying the present invention.

in my method the connector is fabricated by cold plastic deformation or plastic flow in suitable dies by the application of an impact pressure in the range between 25,000 to 500,000 pounds per square inch, depending on the size of the connector. tegral ,1 iorme structure without earn, Weld, or joint, and or unn" rrn strength and character throughout, and possessing the characteristics of a work hardened metal structure to the maximum degree in all portions thereof, in ace rdance with the principles of metallography, and particularly from a microscopic study of the grain structure thereof, and by subjecting the same to the usual tests for tensile strength and hardness. The product, therefore, because of the novel method of production, represents a distinct advance over sin ilar articles fabricated by stamping or turning. The metal used may be electrolytic copper having a purity in excess or 99%. The wall thickness may be reduced beyond that obtained from sheet metal or turning, without loss of strength.

I h ve thus described my invention, but I desire it understood that it is not confined to the particular forms or uses shown and described, the same being merely illustrative, and that the invention may be carried out in other ways without departing from the spirit of my invention, and, therefore, I claim broadly the right to employ all equivalent instrumentaiities coming within the scope of the ap- The resulting product is an in-' pended claims, and by means of which, objects of my invention are attained and new results accomplished, as it is obvious that the particular embodiments herein shown and described are only some of the many that can be employed to attain these objects and accomplish these results.

I claim:

1. An article of manufacture consisting of a plurality of electrical contacts formed into a continuous strip out of a piece of metal; each contact comprising a solid, circu ar-cross-section tip; said tip havi g a forward end of a given diameter and uniformly tapering to a rearward end of a larger than said given diameter; a solid shoulder integrally connected to said rearward end of said tip; a conductor receiving portion integrally connected to said sol d shoulder; and an interconnecting link integrally connected to sai conductor receiving portion and to the solid tip of the following contact.

2. The article of manufacture according to claiml wherein said conductor receiving portion comprises a bare conductor receiving subportion and a conductor insulation re'ceiviu subportion, both said subportions being of U cross-section; and wherein said forward end of said tip is rounded oil.

.3. The article of manufacture according to claim ,1 wherein said tip, shoulder and conductor receiving portion are coaxial with a first axis, while said interconnecting link is on a second axis, parallel to and spaced from said first axis.

References Cited in the file of this patent UNITED STATES PATENTS 375,280 1887 1,559,361 1925 1,642,696 Rateike Sept. 20, 1927 2,234,185 Marinsky et al. Mar. 11, 1941 2,297,785 Lake Oct. 6, 1942 2,346,831 rury Apr. 18, 1944 2,413,539 Ballard Dec. 31, 1946 2,450,529 Sprigg Oct. 5, 1948 2,457,520 Benander Dec. 28, 1948 2,477,849 Adams Aug. 2, 194-9 2,555,754 Morin June 5, 1951 2,569,083 Wilhelm Sept. 25, 1951 2,577,350 Morin Dec. 4, 1951 2,596,528 Carlson May 13, 1952 2,600,190 Batcheller lune 10, 1952 2,778,097 Berg Jan. 22, 1957 

1. AN ARTICLE OF MANUFACTURE CONSISTING OF A PLURALITY OF ELECTRICAL CONTACTS FORMED INTO A CONTINUOUS STRIP OUT OF A SINGLE PIECE OF METAL; EACH CONTACT COMPRISING A SOLID, CIRCULAR-CROSS-SECTION TIP; SAID TIP HAVING A FORWARD END OF A GIVEN DIAMETER AND UNIFORMLY TAPERING TO A REARWARD END OF A LARGER THAN SAID GIVEN DIAMETER; A SOLID SHOULDER INTEGRALLY CONNECTED TO SAID REARWARD END OF SAID TIP; A CONDUCTOR RECEIVING PORTION INTEGRALLY CONNECTED TO SAID SOLID SHOULDER; AND AN INTERCONNECTING LINK INTEGRALLY CONNECTED TO SAID CONDUCTOR RECEIVING PORTION AND TO THE SOLID TIP OF THE FOLLOWING CONTACT. 